

A101794


Numbers k such that 4*k1, 8*k1, 16*k1 and 32*k1 are all primes.


10



45, 90, 675, 885, 3030, 4290, 6870, 13410, 14460, 15855, 17850, 18675, 20625, 21885, 25350, 26820, 26925, 28230, 30525, 30705, 31710, 31785, 33375, 34860, 41685, 41940, 57435, 63420, 63570, 71805, 74025, 78585, 83865, 85230, 93075
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OFFSET

1,1


LINKS



EXAMPLE

4*451 = 179, 8*451 = 359, 16*451 = 719 and 32*451 = 1439 are primes, so 45 is a term.


MATHEMATICA

Select[Range[10^5], And @@ PrimeQ[2^Range[2, 5]*#  1] &] (* Amiram Eldar, May 13 2024 *)


PROG

(PARI) is(k) = isprime(4*k1) && isprime(8*k1) && isprime(16*k1) && isprime(32*k1); \\ Amiram Eldar, May 13 2024


CROSSREFS



KEYWORD

easy,nonn


AUTHOR

Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 16 2004


STATUS

approved



